The forearm has two large bones, the radius and the ulna, which run parallel to one another. The proximal end of the radius is at the lateral side of the elbow and extends all the way to the thumb side of the wrist which is the distal end of the radius (from a reference position in which the palm of the hand faces forward). The radius can also be divided in its other dimensions. For example the palm side of the radius bone is called the “volar” and the other side is called “dorsal.” The volar distal radius therefore refers to the palm side of the distal radius. The most prominent region (the part that sticks out like a ridge line) of the volar distal radius is called the “watershed line.” A distal radius fracture is a common bone fracture of the distal end of the radius in the forearm.
Surgical implantation of a fixation (called a radius plate herein) plate to secure a broken radius has significantly helped revolutionize treatment of distal radius injuries. The plate may be fixed adjacent to the bone to be healed and is held in place using screws. There are many different techniques for treating distal radius fractures including dorsal plating, fragment specific fixation, non-spanning external fixation, volar plating, spanning internal fixation plates.
Locked volar plating is a commonly used technique that has significantly improved the value of treatment. The volar plate has holes and is affixed by screws that run through holes in the plate.
Notwithstanding its value, a well-known complication of volar plating is irritation and/or rupture of the tendons, especially flexor tendons. The idea is to keep the bone fragments of the fracture together securely without causing irritation or rupture of the tendons. The most common way to position the volar plate is to position it at or just proximal to the watershed line of the distal radius.
Other prior art devices for securing are known that affix solely to the radius. These devices normally have an elongated section that extends along the body part of the radius prior to its distal end near the wrist. At the distal end, which is wider than the body, a plate connected to the elongated portion is affixed, normally by screwing into place.
Some common problems with the aforementioned prior art devices are (1) they are difficult to center on the radius bone, (2) they sometimes rotate out of being centered after first being affixed, (3) they are not shaped like the distal end of the radius and may not secure it properly, and (4) they are not shaped properly, and do not have the proper screw holes or locations, to cover every size arm/hand (or at least a large range of arm/hand sizes).